1. Field of the Invention
The present invention relates to a silver halide photographic light-sensitive material. In particular, the present invention relates to an ultrahigh contrast silver halide photographic light-sensitive material which is processed by using an image setter and automatic processor used for a photomechanical process.
2. Description of the Background
As one of light exposure methods for photographic light-sensitive materials, the so-called scanner type image-forming method is known, in which an original is scanned, and light exposure is preformed on a silver halide photographic light-sensitive material based on the image signals obtained by the scanning to form a negative or positive image corresponding to the original image. As light sources of light exposure apparatuses for this method, HeNe laser (633 nm), red semiconductor laser (670 nm to 680 nm) and LED (660 nm to 680 nm) are widely used. Further, when an image is directly printed on a printing plate without any reversal process after the image is outputted on a film from a scanner, or for a scanner light source having a soft beam profile, light-sensitive materials for scanner having an ultra high contrast property are desired. Furthermore, highly sensitive light-sensitive materials are required in the scanning process in order to shorten the process, obtain high resolution and prolong the lifetime of the light source.
Meanwhile, various patent documents have been published so far for sensitizing dyes exhibiting high sensitivity and little residual color when they are used with a HeNe light source or the like. Examples of such dyes include, for example, trinucleus cyanines (see, for example, Japanese Patent Laid-open Publication (KOKAI, hence force referred to as “JP-A”) No. 62-157057, JP-A-1-47449, JP-A-3-259135, JP-A-2-161424, JP-A-4-318542), trinucleus melocyanines (see, for example, JP-A-3-171135, JP-A-5-224330), trimethine cyanines (see, for example, JP-A-2-297541, JP-A-4-57046) and tetramethine melocyanines (see, for example, U.S. Pat. No. 5,578,414). Further, light-sensitive materials utilizing the aforementioned sensitizing dyes and a hydrazine derivative in combination have also been disclosed (see, for example, U.S. Pat. No. 5,578,414, JP-A-6-194771, Japanese Patent Nos. 2926453 and 3086983).
In the development of the aforementioned light-sensitive materials, it has become frequent to use an automatic processor in view of quick operation, simplicity and handling. In recent years, smaller replenishing amount, quicker operation and lower silver content of light-sensitive materials are increasingly strongly desired, and one of means for satisfying these requirements is increase of activity of developer. In the processing of monochrome light-sensitive materials, the activity can be increased by using a higher concentration of developing agent. However, there is a problem that degradation of the developer due to air oxidation becomes marked. Further, use of smaller thickness of light-sensitive material (for example, use of thinner protective layer) is also effective for realizing quicker processing. However, if a light-sensitive material of a low silver content is quickly processed, there are caused a problem of residual color and a problem that fluctuations of photographic properties (dot % fluctuation, decrease of density etc.) become significant. Furthermore, a lower silver bromide content in silver halide is also effective for attaining quicker processing. However, it suffers from a problem of generation of uneven processing by solution physical development, and thus use of a higher silver bromide content is required.
Therefore, an object of the present invention is to provide a silver halide photographic light-sensitive material suitable for use with a scanner and image setter utilizing a HeNe laser, red semiconductor laser or LED as a light source, in which the problems of uneven processing and residual color can be suppressed even after a long term running with a low silver content, and thus stable photographic performance can be obtained.